1. Field of the Invention
The present invention relates generally to a supersonic sound emission device and, more particularly, to a supersonic sound emission device that prevents birds or other animals species from causing damage.
2. Description of the Prior Art
Various means are in existence, which prevent birds and similar animals from causing direct or indirect damage to humans and other animals and property. Unattended prevention methods against damage caused by the bird species such as sparrows, crows, or pigeons have been known. Such devices as "scarecrows" drive away the birds and are placed in scattered installations in rice patties or the like. There are other ways to drive off the birds such as the mounting of multiple "wooden clappers", which generate a noise by wind movement. It is also noted that drive-off devices using large explosive sounds such as those made by firecrackers are in existence.
An unpleasant sanitation problem results from the droppings of pigeons, which form their nests under house eaves. In order to prevent this problem, the inhabitants have hung, about their homes, paper blankets or the like, which contain drawings such as a "huge eye".
Another problem has arisen from the proliferation of power cables. An increase of accidents have been caused by the birds' alighting on the power cables.
The effectiveness of the conventional "scarecrow" or "huge eye" devices depend upon appeal to the birds' vision or to their sense of hearing in order to generate sufficient impression signifying vigilance or terror. Thus, with such devices, the birds are prevented from even approaching such locations.
However, none of these means present a complete solution, while some cannot even be practiced due to site location. Accordingly, the provision of effective means that do not require special conditions for adaptation to various locations and which can be easily installed have been long awaited.
It is an easy task to present a unit that merely emits supersonic sounds. However, there are various problems in order to present an effective dispersing device for birds.
First, there is the problem of power source for the device. Power supply from a commercial electric power source may be considered, but it carries the limitation that the commercial electric power source must first exist in the vicinity. When the situs of the device is near a house, it is no problem, but when the device is far from any commercial electrical power source, a long cable becomes necessary. This is not only troublesome but is also dangerous. On the other, should batteries be used, the continuous cost to replace the batteries is expensive, and even in the case where rechargeable secondary batteries are used, frequent charging requires excessive care and cost.